Abstract: α-methylstyrene-acrylonitrile (α-MSAN) copolymers were synthesized by emulsion polymerization and was blended with polymethyl methacrylate (PMMA) via melt blending. The compatibility of PMMA/α-MSAN blends was investigated using transmission electron microscopy (TEM) and dynamic mechanical analysis (DMA). It was found that when the acrylonitrile contents in α-MSAN was between 15 % and 25 %, PMMA/α-MSAN blends were compatible, and the compatibility became better with increasing acrylonitrile content. When acrylonitrile content was more than 30 %, PMMA/α-MSAN blends became incompatible.

Key words: α-methylstyrene/acrylonitrile copolymers, polymethyl methacrylate, emulsion polymerization, compatibility